The LC50 is used in determining toxicity to aquatic species. It is the aqueous concentration of a test chemical that results in 50% mortality in the species during a predetermined time period. The LC50 measurde for fathead minnows, during a 96-h exposure test, is 151 mg/L for caffeine(C8H10N4O2) and 44.1 mg/L for TCE(C2Cl3H).
Is the LC50 exceeded if the aquaous concentration of caffeine is 6.2 X 10^-4 M and TCE is 4.5 X 10^-4 M?